Internal combustion engine control



1939- 4 M, J. FINNEGAN ET AL 2,142,746

INTERNAL COMBUSTION ENGINE CONT1OL Filed Jan. 9, 1936 V 2 sneaks-shes. 1

I a v 5 V 5 6- g No.3 (6 No.2 C

34 F F l D ORNEYTJM Jan. 3, 1939. l M. J. FINNEGAN ET AL 1 2,142,746

INTERNAL COMBUSTION ENGINE CONTROL Filed Jan. 9, 1936 2 Sheets-Sh e et 2 INVENTORS. Mar/1 J fiimeyafl Howard Beer BY IFIIIIIIJZEZ Patented Jan. 3, 1939 UNITED STATES PATENT OFFICE INTERNAL COMBUSTION ENGINE CONTROL Martin J. Finnegan, New York, N. -Y., and How ard Baer, Jersey City, N. J., assignors to Eclipse Aviation Corporation, East Orange, N. J., a

corporation of New Jersey Application January 9, 1936, Serial No. 58,324

5 Claims.

to any internal combustion engine adapted to drive a load which has the objectionable tendency to continue in motion after de-energiz'ation of the engine.

If an airplane engine stalls for any reason, it is desirable to bring both the engine and its propeller'to a dead stop in order to decrease the propeller drag and prevent any aggravation of the injurious effects which such failure of the engine produces, It is particularly necessary that this free rotation of the propeller be prevented in any installation where the propeller is located oii the center line of the plane, as for example, in a multi-engine plane. It, is accordingly anobject of the present invention to prevent such continued rotation of the propeller of an airplane engine which has for any reason failed.

In this respect the invention isan improvement upon that of Romeo M. Nardone, as disclosed in his Patent No. 1,967,966 of July 24, 1984, the improvements including:

First, the extension of the concept to include a plurality of such rotation-arrestingdevices, to be actuated by means energized from a common source;

' to three engines.

Secondly, the provision of novel heat responsive means for controlling such energization;

Thirdly, the provision of selective energizing means; and- Fourth, the provision of electromagnetic actuation for each rotation arresting device.

In the drawings,

Fig. 1 is a'schematic representation of the parts involved in one embodiment of the invention when applied to two engines;

Fig. 2 shows the invention applied to three engines;

. Fig. 3 is 'a diagrammatic view of a second embodiment, as applied to two engines; and

Fig. 4 shows thissecond Referring first to Fig. 1, reference character 5 designates one arm of a bellcrank having at its outer end a formation 6 adapted to receive a link embodiment applied or other operating connection leading to the friction brake 8 operating, when drawn tight, to arrest the rotation of the propeller driving shaft 1, the saidrotation arresting device corresponding in function to the friction brake operating connections shown at 99, I00, I02 and at 91 of Fig. 1 of the above identified Nardone patent, and constituting the means for arresting rotation of the engine driven propeller shaft 29 of said patent. A similar bellcrank arm 5' and formation 6' is shown for operation of a duplicate mechanism 8' for arresting the motion of a .propeller shaft 1' of a second internal combuselectromagnetic device, that for the bellcrank 5 being indicated at l and that for the bellcrank at H, and both being adapted to be energized from a common source l3 through parallel connections [4 and and a plurality of switches A, B, C, D, adapted for selective actuation in accordance with the thermal conditions in or adjacent the corresponding internal combustion engines (not shown).

Reference characters T1 and T2 designate the two separately acting elements of a heat responsive unitor thermostat adapted to actuate the switch contacts A and B respectively, to open or close said contacts in such manner that position of said contacts will correspond to that indicated in the drawings when the associated engine is not running, the contacts moving to new positions when'the engine has been running for a sufiicient interval to generate the necessary heat increment to cause such movement. Switches C, D, respond similarly to the, thermal condi-' stat T2 will take a longer interval, say severalminutes. Likewise, there is a diiierential-action onthe part of thermostats T3 and T4 the latter being of the quickly acting type and the former of the more slowly acting type whereby switch D will open almost immediately upon the startingof engine No. 2 while the closing of switch C will plied, and to the other of which the rotation arresting device 5' is applied, the starting of the engines land 2 will develop the necessary heat rise in devices T1 and T4 to cause movement of the switches A and D to the open position simultaneously, or in rapid sequence-it being assumed that both engines will be started substantially simultaneously. Several minutes later, when switches B and C move to the closed position, the solenoids l and II will remain de-energized, since the circuit to solenoid I0 is now open at switch A, and the circuit to solenoid II is now open at switch D. In other words, the closure of switches B and C has no effect, for the circuits thereto are open at the points A and D, respectively, as noted. This condition prevails during normal flight, that is, unless and until an enenergization of thesolenoid in producing a counterclockwise shifting of the bellcrank and hence an application of the brake to the said engine No. l.

Now if engine No. 2 should thereafter fail, so

that both engines are dead, the resultant opening of switch C will break the circuit just traced to solenoid i0, and solenoid II also will remain deenergized, due to the open condition of switch B of the latter circuit. However, should engine No. 2 be the first to fail, rather than engine No. 1, the resultant closure of switch D, coupled with the fact that switch B is also closed (due to the heated condition of engine No. 1 and T2), completes the circuit to solenoid I l to apply the brake to engine No. 2 by way of conductor l5, solenoid II, switches D and B, conductor 22, conductor 23 to battery l3.

The result is to cause application of the engine rotation arresting means automatically when one, but not both, engines have failed, while permitting the automatic release of the brake when both engines have failed, and also to prevent application of either brake prior to any' actual failure of one engine.

When the embodiment of Fig. 1 is applied to three engines the arrangement is preferably as shown in Fig. 2 wherein there is an additional thermostatically controlled set of switches E and F adapted to be actuated by slow acting and quick acting thermostats T5 and Ts respectively, the switch F being in circuit withthe solenoid l2 which applies the brake to engine No. 3 through mechanism corresponding to that of engines No. 1 and No. 2 previously described; and the switch E is in one branch of the circuit to the solenoid l0 as well as being also in circuit under certain conditions with the solenoid ll. Likewise the quick acting switches A and D are in circuit with the solenoids Ill and lLrespectively, of their associated engines, while the slow acting switches B and C are adapted for control of the circuits to the solenoids of the other enginesengines No. 2 and No. 3 in the case of switch B and engines No. 1 and No. 3 in the case of switch C. By reason of this arrangement of the switches and controlling circuits, all solenoids will remain de-ener'gized during normal flight with all three engines in the running condition and therefore generating sufiicient heat to hold switches F, A

and D open, but if any one of the three engines should fail the resulting closure of one of the three switches just referred to will close the circuit to the corresponding solenoid I0, I I or l2 to apply the brake to the said engine and thereby arrest its rotation. Thus, for example, if engine No. 3 should fail during flight the solenoid l2 would become energized by reason of the fact that the switches are in the following positions during normal fiight:

Switches A, D and F are open Switches B, C and E are closed but the cooling-off of thermostat Ts due to the stalling of engine No. 3 would cause switch F to close and thus complete a circuit to the solenoid I! which is traceable from the battery 13 through conductors 3|, 32, switch B, conductor 34, the now closed switch F and conductor 35 to the solenoid i2, the return circuit being by the way of conductors 36, 31 and 38; Thus, the brake is applied to engine N0. 3, but not to either of the other two engines (which, under the assumed conditions, will still be in operation), since the circuit to solenoid I0 is still open at the switch A while the circuit to the solenoid H is still open at the switch D.

In choosing the time interval for the slow acting thermostats T5, T2 and T3 it is suggested that the interval be great enough to embrace the normal interval elapsing between the starting of the first and the starting of the last of the engines to be started. In the case of a three-motor plane this interval may extend over a period of several minutes; hence the foregoing suggestion that the slow acting thermostat be set to act not sooner than several minutes after" the first turning-over of the engine. If so set there is' an assurance that the three engines will be started before any one of the three slow acting switches E, B or. C moves to the closed circuit position. Thus, there is an assurance that none of the solenoids will be prematurely energized.

In the modification of the invention shown, in Figs. 3 and 4 each set of switches AB, CD and EF (the latter being employed only when there is a third engine as in Fig. 4) is actuatedby a single thermostatic device so that the opening of the switch A for example, is simultaneous with the closing of the switch B and likewise with respect to switches C and D for engine No. 2 and switches E and F for engine No. 3. The result is the same however, as in Figs. 1 and 2, that is, the starting of the engines causes a movement of the switches -A, C and E to the open position thereby preventing energization of any one of the solenoids I0, II' or i2, notwithstanding the simultaneous closure of the switches B, D and F, since each solenoid is in a circuit with at least one of the normally open switches. However, in the event of a subsequent failure of one engine the resulting closure of its normally open switch will com plete a circuit to its solenoid by way of said now closed switch and the normally closed switch of the related engine. Thus, for example, failure of engine No. 1 in the two-motor arrangement of Fig. 3 will cause an energization of solenoid II, the current flowing from source II by way of conductors 5| and 52 to the switch A and from said point by way of conductor 53 to the switch D which is closed during flight, and from said point by way of conductor It to the solenoid I 0' the return circuit being by way of conductor ll. A similar failure in the three-engine arrangement of Fig. 4 would likewise result in energization of the solenoid iii, the circuit being from the source i3 by way of conductors BI, 62 and 03 to the solenoid l0 and returning by way of conductors 64, 65, switch F (closed during flight), conductors 66 and 61 and the now closed switch A (although normally open during flight-that is, with the engine running) and back to the source It by way of conductors 68 and 89.

What we claim is:

1. The combination with an internal combustion engine and propeller shaftrotated by said engine,-of means for arresting the rotation oi said propeller shaft, and temperature controlled electromagnetic means for controlling said arresting means.

2. The combination with an internal combustion engine and propeller shaft rotated by said engine, of means for arresting the rotation of said propeller shaft, and electromagnetic means for controlling said arresting means, a circuit includ-- ing a source of current to energize said electromagnetic means, and means normally holding said circuit open said last named means including a switch in said circuit, and means responsive to the heat developed upon operation oi the engine to move said switch to the open circuit position.

3. The combination with an internal combustion engine and propeller shaft rotated by said engine, oi means for arresting the rotation of said propeller shaft, and electromagnetic means for controlling said arresting means, a circuit including a source of'current to energize said electromagnetic means, and means normally holding said circuit open said last named means including a switch in said circuit, and means responsive to the heat developed upon operation oif the englue to move said switch tothe open circuit position said heat responsive means being also adapted to return the switch .to the closed position when the engine cools to a predetermined extent after stopping.

4. The combination with a plurality of internal combustion engines, of a corresponding plurality of brakes engageable with the respective propeller drives, electromagnetic control means for said brakes, and means including a common source of energy for operation of said electromagnetic control means said last named means also including a circuit having a series of switches therein, and means individual to each engine to control operation of a selected one of said switches.

5. The combination with a plurality of internal combustion: engines, of a. corresponding plurality oi" brakes operable upon the respective engines, actuating means for said brakes. and means individual to each engine to control application of the brake to a selected engine. and the release 01' the brake from all engines whenever the brake being applied is not the first in the series.

mam J. FINNEGAN. HOWARD BAER. 

